81653709571200 has 2304 divisors, whose sum is σ = 338277377433600. Its totient is φ = 19207302266880.

The previous prime is 81653709571097. The next prime is 81653709571219. The reversal of 81653709571200 is 217590735618.

81653709571200 is a `hidden beast` number, since 8 + 1 + 6 + 537 + 0 + 95 + 7 + 12 + 0 + 0 = 666.

It is a hoax number, since the sum of its digits (54) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 29509832217 + ... + 29509834983.

It is an arithmetic number, because the mean of its divisors is an integer number (146821778400).

Almost surely, 2^{81653709571200} is an apocalyptic number.

81653709571200 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81653709571200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (169138688716800).

81653709571200 is an abundant number, since it is smaller than the sum of its proper divisors (256623667862400).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81653709571200 is a wasteful number, since it uses less digits than its factorization.

81653709571200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2916 (or 2880 counting only the distinct ones).

The product of its (nonzero) digits is 3175200, while the sum is 54.

The spelling of 81653709571200 in words is "eighty-one trillion, six hundred fifty-three billion, seven hundred nine million, five hundred seventy-one thousand, two hundred".